DIY loudspeakers using 32-liter enclosures

Hello loudspeaker design gurus! Please solve the following problem.
I have two unused 32-liter enclosure kits that are originally meant for subwoofers. I intend to build two-way (or three-way) vented-box loudspeakers using these enclosures. Thiele-Small parameters are just right for my enclosures if I choose 8'' Visaton WSP 21 S woofers which have a fairly low resonance frequency of 28 Hz and VAS=80 liters and QTS=0,28.
But what kind of tweeters and crossovers should I put in? If I use a tweeter with a low resonance frequency and a first-order textbook Butterworth crossover, do I have a chance of success without measuring equipment? Or is someone aware of a two-way or three-way design using approximately 32-liter enclosures that I could copy?

Yours humbly
bat

 

Somebody may help you out here, but I would direct you to www.diyaudio.com and ask in their loudspeaker forum.

 

Are these really nice boxes, or just crappy car speaker cabs? Unless you have a driver which matches the makers holes, expect a headache cos you will be filling and cutting to make it fit. I have just been converting a B139 hole [oval] to a 10" round, so I have enjoyed this too..

What size is your baffle, and which country are you in? Nearest cheap UK kit I have noticed was the SEAS Neon kit 40 litres 8" bass £205 at:

www.falcon-acoustics.co.uk

that would solve your x-over query as it's in the price.

BTW, a peerless XLS 10" would go to - 4dB@30Hz, 85dB/watt, 25 Hz tuning with 1ohm series resistance [inductor+cheap cable!]

 

My boxes are made of 19 mm MDF. I think they will be quite nice and solid if I assemble them carefully. The baffle is 340 x 402 mm and depth of the box 340 mm. The baffle has two round holes; a 186 mm hole and a 90 mm hole. I'm located in Finland.
What I originally had in mind was to find a woofer that fulfills the Thiele-Small parameters for my cabinets and fits the hole nicely (the Visaton woofer I mentioned is 184 mm wide and has quite flat response up to 3 kHz); then find a tweeter that has a low resonance frequency; then build the speakers with a very simple first-order crossover and perhaps do some tweaking with the inductor and/or capacitor if the speakers don't sound super at once. What's wrong with this scenario?
Someone recommended me the Seas Njord design:
http://www.seas.no/kit/Njord.pdf
but it is designed for a 40-liter cabinet size and I have only 32-liter cabinets.
Seas Trym is designed for 34 liters but I suspect that it would be very expensive.
http://www.seas.no/trym.htm

 

I think if yu are using an 8 incher, that means the xover freq will be fairly low to avoid break up, which means the tweeter will receive more power.
Now the 1st order xover means a tweeter gets more power too, so I would tend to think use a really good tweeter like a scanspeak, or morel, and also use it with a 2nd or even 3rd order rolloff. difficult without a bit of software

32 litres is a really commonish size, largeishby uk standards, check out wilmslow home studio monitor size.

so if you download winisp, and get your box size, you can model any number of woofers, then find a good one used in regular designs and copy that., hows that?

check out solen, canada, goto design, goto kits, and click on volt hsm2 that is about right methinks

http://www.solen.ca/

 

You could buy the FALCON TAMBOUR kit - 32 litres(!) in a sealed box. The kit includes drivers and crossovers. It uses an 8" Focal bass driver and 1" tweeter - £198 + postage

see the 2nd kit [I.B.] on the page:

http://www.falcon-acoustics.co.uk/pl28p2.htm

Some sizes for the Focal 8" driver cut-outs. I think they always use the same chassis, but I could be wrong:

http://www.focal.tm.fr/gb/compo/archives/midbass/plan/8v4411.htm